HomeCummins/OnanCummins/Onan DGAC

Cummins/Onan DGAC Generator Set

The Cummins/Onan DGAC is a 25 kW 2-D Diesel standby generator set powered by a 6A3.4 engine. It is available at 12 V, 3-phase and 60 Hz. It holds about 8.5 L (2.2 gal) of oil and 16.8 L (4.4 gal) of coolant. Starting uses 1 group-31 battery rated 625 CCA at 12 V.

25 kW
Standby
8.5 L
Oil capacity
2
Document types

How to read your Cummins/Onan serial & model number →

Typical fuel consumption for 25–30 kW Diesel generators →

Compare with other 25–30 kW Diesel generators →

Service parts for the DGAC

Grouped by system, with how many of each the parts manual calls for.

Oil system

1 required

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

Fuel2-D Diesel
Frequency60.0 Hz
Standby power25 kW
Oil capacity8.5 L
Voltage options12 V
PhaseI,3
Power factor0.8
Battery group31
Battery cranking625 CCA
Battery voltage12 V
Battery quantity1
Coolant capacity16.8 L

Engine

6A3.4
Rated speed1800 rpm

Filters & service parts

model family
ItemSpecCapacityPart #Interval
Air filter
Fuel filter50 hr
Oil filterChange Fuel Filter51592200 hr Amazon eBay FridayParts $15.89
Battery
Belt
Coolant
Oil50 hr
Spark plug

Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number.

Common questions

What is the power rating of the Cummins/Onan DGAC?

The Cummins/Onan DGAC is rated 25 kW standby.

What engine is in the Cummins/Onan DGAC?

The Cummins/Onan DGAC is powered by the 6A3.4 engine.

What kind of fuel does the Cummins/Onan DGAC run on?

The Cummins/Onan DGAC runs on 2-D Diesel.

What oil filter does the Cummins/Onan DGAC use?

The Cummins/Onan DGAC uses oil filter part number 51592.

Troubleshooting

6

Symptoms & remedies

SymptomRemedy
PRE HI ENGINE TEMP lamp lights. Engine continues to operate.1. Green RUN lamp lights following engine start-up. 2. Indicates engine has begun to overheat and engine temperature has risen to approximately 202°F (94°C). If generator is powering non-critical and critical loads and cannot be shutdown, use the following: a. Reduce load if possible by turning off non-critical loads. b. Check air inlets and outlets and remove any obstructions to airflow. c. Open doors or windows in generator area to increase ventilation. If engine can be stopped, follow procedure in step 3.
HI ENG TEMP lamp lights. Engine shuts down.4. Indicates engine has overheated (engine temperature has risen above 222°F/106°C) or coolant level is low (sets with coolant level sensor). Allow engine to cool down completely before proceeding with the following checks: a. Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. b. Check for obstructions to cooling airflow and correct as necessary. c. Check for a slipping fan belt and tighten if loose. d. Reset control and restart after locating and correcting problem. Contact an authorized dealer or distributor if none of the above.
PRE LO OIL PRES lamp lights. Engine continues to operate.4. Indicates engine oil pressure has dropped to 20 psi (138 kPa). If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 5 procedure. If engine can be stopped, follow procedures in step 5.
LO OIL PRES lamp lights. Engine shuts down.5. Indicates engine oil pressure has dropped to 14 psi (97 kPa). Check oil level, lines and filters. If oil system is okay but oil level is low, replenish. Reset control and restart. Contact an authorized dealer or distributor if oil pressure is not in the range of 30 to 55 psi (206 to 379 kPa).
OVERCRANK lamp lights and engine stops cranking.6. *12-Light Panel Only. Engine runs, shuts down, and LO OIL PRES lamp lights.
Engine runs and then shuts down, OVERSPEED lamp lights.7. *12-Light Panel Only.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan DGAC troubleshooting guide (23 entries) →

Parts

4
Part #DescriptionQtySystem
193-0244Sender, Pressure - 0i11Sensor Amazon eBay
309-01691 Begin Spec G 25 261Service part / kit Amazon eBay
718-1067Screw. Hex Head1Service part / kit Amazon eBay
960-0135Service part / kit Amazon eBay $19.00

Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Available documents

Parts manual — 0932-0112 Onan Post-Sale Literature Index (07-1998) (Cummins/Onan)Parts manual — 934-0236 Onan DGAB DGAC DGAD (Spec F) DGAE (Spec C) DL4 DL6 (Spec C-F) DLT (Spec A-C) A41 A61 (Spec E) A61T (Spec B) (08-2011) (Cummins/Onan)Service manual — 934-0125 Onan DGAB DGAC DGAD DGAE Diesel Genset Operators manual (08-1990) (Cummins/Onan)
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